U.S. patent application number 13/423519 was filed with the patent office on 2012-08-09 for method for treating an extracted tobacco pulp and tobacco products made therefrom.
This patent application is currently assigned to R.J. Reynolds Tobacco Company. Invention is credited to Crystal Dawn Hege Byrd, Anthony Richard Gerardi, Yan Pu, Charles Bradford Rhoades, JR..
Application Number | 20120199145 13/423519 |
Document ID | / |
Family ID | 46599817 |
Filed Date | 2012-08-09 |
United States Patent
Application |
20120199145 |
Kind Code |
A1 |
Byrd; Crystal Dawn Hege ; et
al. |
August 9, 2012 |
METHOD FOR TREATING AN EXTRACTED TOBACCO PULP AND TOBACCO PRODUCTS
MADE THEREFROM
Abstract
The invention provides a method of producing a tobacco
composition for use in a tobacco product, the method including
treating a tobacco pulp with supercritical carbon dioxide. The
treated tobacco pulp may exhibit a benzo[a]pyrene concentration
lower than the initial benzo[a]pyrene concentration and/or a TSNA
concentration lower than the initial TSNA concentration. The
treated pulp can be introduced into tobacco products including
smoking articles, smokeless tobacco products, and
aerosol-generating devices configured for non-combustion of plant
materials.
Inventors: |
Byrd; Crystal Dawn Hege;
(Lexington, NC) ; Pu; Yan; (Winston-Salem, NC)
; Gerardi; Anthony Richard; (Winston-Salem, NC) ;
Rhoades, JR.; Charles Bradford; (Clemmons, NC) |
Assignee: |
R.J. Reynolds Tobacco
Company
|
Family ID: |
46599817 |
Appl. No.: |
13/423519 |
Filed: |
March 19, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12949361 |
Nov 18, 2010 |
|
|
|
13423519 |
|
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Current U.S.
Class: |
131/298 ;
131/297; 131/352 |
Current CPC
Class: |
A24B 15/24 20130101;
A24B 15/245 20130101 |
Class at
Publication: |
131/298 ;
131/297; 131/352 |
International
Class: |
A24B 15/24 20060101
A24B015/24; A24B 13/00 20060101 A24B013/00 |
Claims
1. A method of producing a tobacco composition for use in a tobacco
product, the tobacco composition characterized by a reduced
benzo[a]pyrene concentration, comprising: mixing an extracted pulp
of a cured tobacco material having a first benzo[a]pyrene
concentration with supercritical carbon dioxide to provide intimate
contact between the extracted pulp and the supercritical carbon
dioxide; maintaining the intimate contact for a time and at a
temperature sufficient to form a treated tobacco pulp exhibiting a
second benzo[a]pyrene concentration lower than the first
benzo[a]pyrene concentration; and separating the treated tobacco
pulp from a residual supercritical carbon dioxide extract
comprising components of the tobacco material that are soluble in
the supercritical carbon dioxide.
2. The method of claim 1, wherein the cured tobacco material of the
extracted pulp comprises ground fire-cured tobacco.
3. The method of claim 2, wherein the extracted pulp is an aqueous
extracted tobacco material.
4. The method of claim 1, wherein the pressure at which the mixing
is conducted is about 10 MPa or greater.
5. The method of claim 1, wherein the pressure at which the mixing
is conducted is about 20 MPa or greater.
6. The method of claim 1, wherein the pressure at which the mixing
is conducted is between about 10 MPa and about 40 MPa.
7. The method of claim 1, wherein the temperature at which the
mixing is conducted is about 40.degree. C. or greater.
8. The method of claim 1, wherein the temperature at which the
mixing is conducted is about 50.degree. C. or greater.
9. The method of claim 1, wherein the temperature at which the
mixing is conducted is between about 40.degree. C. and about
60.degree. C.
10. The method of claim 1, wherein the mixing is conducted for a
period of at least about 15 minutes.
11. The method of claim 1, wherein the mixing is conducted for a
period of at least about 30 minutes.
12. The method of claim 1, wherein the mixing step comprises mixing
the extracted pulp with supercritical carbon dioxide and
ethanol.
13. The method of claim 12, wherein the ethanol is present in an
amount of about 10% to about 30% by volume of the supercritical
carbon dioxide and ethanol.
14. The method of claim 1, wherein the first benzo[a]pyrene
concentration is at least about 200 ng/g and the second
benzo[a]pyrene concentration is less than about 80 ng/g.
15. The method of claim 1, wherein the TSNA concentration of the
treated tobacco pulp is less than that of the extracted pulp of
cured tobacco material.
16. The method of claim 15, wherein the extracted pulp of cured
tobacco material has a TSNA concentration of greater than about
5,000 ng/g and the treated tobacco pulp has a TSNA concentration of
less than about 2,000 ng/g.
17. The method of claim 1, further comprising adding a tobacco
extract to the treated tobacco pulp to form a tobacco
composition.
18. The method of claim 17, wherein the tobacco extract is an
aqueous extract.
19. The method of claim 17, wherein the tobacco extract and the
treated tobacco pulp are derived from the same tobacco sample.
20. The method of claim 1, further comprising introducing the
treated tobacco pulp into a tobacco product.
21. The method of claim 20, wherein the tobacco product is selected
from the group consisting of smoking articles, smokeless tobacco
products, and aerosol-generating devices configured for
non-combustion of plant material.
22. The method of claim 20, wherein the tobacco product is a
smokeless tobacco composition selected from the group consisting of
moist snuff, dry snuff, chewing tobacco, tobacco-containing gums,
and dissolvable or meltable tobacco products.
23. A tobacco product comprising an extracted pulp of a cured
tobacco material, wherein the extracted pulp of cured tobacco
material is characterized as having a B[a]p concentration of less
than about 80 ng/g.
24. The tobacco product of claim 23, wherein the extracted pulp is
characterized as having a TSNA concentration of less than about
2,000 ng/g.
25. The tobacco product of claim 23, further comprising a tobacco
extract carried by the extracted pulp.
26. The tobacco product of claim 25, wherein the tobacco extract is
an aqueous extract.
27. The tobacco product of claim 23, wherein the tobacco extract
and the extracted pulp of cured tobacco material are derived from
the same tobacco sample.
28. The tobacco product of claim 23, wherein the tobacco product is
in the form of a smokeless tobacco composition, a smoking article,
or an aerosol-generating device configured for non-combustion of
plant material.
29. The tobacco product of claim 28, wherein the tobacco product is
in the form of a smokeless tobacco composition selected from the
group consisting of moist snuff, dry snuff, chewing tobacco,
tobacco-containing gums, and dissolvable or meltable tobacco
products.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S.
application Ser. No. 12,949,361, filed Nov. 18, 2010, which is
hereby incorporated by reference in its entirety.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to products made or derived
from tobacco, or that otherwise incorporate tobacco, and are
intended for human consumption. In particular, the disclosure
relates to compositions or formulations incorporating tobacco, such
as those intended to be employed in a smokeless form.
BACKGROUND OF THE INVENTION
[0003] Cigarettes, cigars, and pipes are popular smoking articles
that employ tobacco in various fauns. Such smoking articles are
employed by heating or burning tobacco to generate aerosol (e.g.,
smoke) that may be inhaled by the smoker. Tobacco may also be
enjoyed in a so-called "smokeless" form. Particularly popular
smokeless tobacco products are employed by inserting some form of
processed tobacco or tobacco-containing formulation into the mouth
of the user. See for example, the types of smokeless tobacco
formulations, ingredients, and processing methodologies set forth
in U.S. Pat. Nos. 1,376,586 to Schwartz; 3,696,917 to Levi;
4,513,756 to Pittman et al.; 4,528,993 to Sensabaugh, Jr. et al.;
4,624,269 to Story et al.; 4,991,599 to Tibbetts; 4,987,907 to
Townsend; 5,092,352 to Sprinkle, I I I et al.; 5,387,416 to White
et al.; 6,668,839 to Williams; 6,834,654 to Williams; 6,953,040 to
Atchley et al.; 7,032,601 to Atchley et al.; and 7,694,686 to
Breslin et al.; US Pat. Pub. Nos. 2004/0020503 to Williams;
2005/0115580 to Quinter et al.; 2005/0244521 to Strickland et al.;
2006/0191548 to Strickland et al.; 2007/0062549 to Holton, Jr. et
al.; 2007/0186941 to Holton, Jr. et al.; 2007/0186942 to Strickland
et al.; 2008/0029110 to Dube et al.; 2008/0029116 to Robinson et
al.; 2008/0029117 to Mua et al.; 2008/0173317 to Robinson et al.;
2008/0196730 to Engstrom et al.; 2008/0209586 to Neilsen et al.;
2008/0305216 to Crawford et al.; 2009/0065013 to Essen et al.; and
2009/0293889 to Kumar et al.; PCT WO 04/095959 to Arnarp et al.;
and U.S. patent application Ser. No. 12/638,394, filed Dec. 15,
2009, to Mua et al.; each of which is incorporated herein by
reference.
[0004] One type of smokeless tobacco product is referred to as
"snuff." Representative types of moist snuff products, commonly
referred to as "snus," are manufactured in the United States and
Europe, particularly in Sweden. See, for example, Bryzgalov et al.,
1N1800 Life Cycle Assessment, Comparative Life Cycle Assessment of
General Loose and Portion Snus (2005). In addition, certain quality
standards associated with snus manufacture have been assembled as a
so-called GothiaTek standard. Exemplary smokeless tobacco products
include CAMEL Snus, CAMEL Orbs, CAMEL Strips and CAMEL Sticks by R.
J. Reynolds Tobacco Company; REVEL Mint Tobacco Packs and SKOAL
Snus by U.S. Smokeless Tobacco Company; and MARLBORO Snus and
Taboka by Philip Morris USA.
[0005] Various treatment methods and additives have been proposed
for altering the overall character or nature of tobacco materials
utilized in tobacco products. For example, additives or treatment
processes have been utilized in order to alter the chemistry or
sensory properties of the tobacco material, or in the case of
smokable tobacco materials, to alter the chemistry or sensory
properties of mainstream smoke generated by smoking articles
including the tobacco material. See, for example, Leffingwell et
al., Tobacco Flavoring for Smoking Products, R.J. Reynolds Tobacco
Company (1972), which is incorporated herein by reference. In
addition, tobacco materials have been processed or blended in a
manner designed to achieve certain sensory or chemistry
characteristics. See, for example, U.S. Pat. No. 7,025,066 to
Lawson et al. and US Pat. Pub. No. 2008/0245377 to Marshall et al.,
which are incorporated herein by reference.
[0006] It would be desirable to provide an enjoyable form of
tobacco product, such as a smokeless tobacco product, and to
provide processes for preparing tobacco-containing compositions
suitable for use in smokeless tobacco products.
SUMMARY OF THE INVENTION
[0007] The present invention relates to a tobacco product, such as
a smokeless tobacco product (e.g., moist snuff, dry snuff, chewing
tobacco, tobacco-containing gums, and dissolvable or meltable
tobacco products) intended or configured for insertion into the
mouth of a user, and to processes for preparing a formulation
suitable for use within such a tobacco product. The tobacco
products of the invention include a flavorful tobacco composition
such as one having the form of a fire-cured tobacco extract. In one
embodiment, the invention provides fire-cured tobacco extracts that
exhibit distinctive sensory characteristics associated with
fire-cured tobacco (e.g., smoky aroma or flavor), while also
exhibiting advantageous chemical composition differences as
compared to fire-cured tobacco in whole form, such as reduced
levels of benzo[a]pyrene or other polycyclic aromatic
hydrocarbons.
[0008] The extract is typically an aqueous extract of the cured
tobacco material, but certain other polar protic solvents or
co-solvent mixtures that include water can be used without
departing from the invention. The concentration of benzo[a]pyrene
in the extract is typically no more than about 10 ppb and often no
more than about 5 ppb.
[0009] Although smokeless tobacco composition are particularly
important types of tobacco products that would benefit from the
extracts of the invention, other tobacco products can also benefit
from such flavorful tobacco compositions, such as smoking articles
(e.g., cigarettes) or aerosol-generating devices that contain
tobacco or tobacco components but which do not combust tobacco or
other plant material. Typically, the tobacco product will comprise
a tobacco material or a non-tobacco plant material as a carrier for
the extract.
[0010] In another embodiment, the extract of the invention is used
to form a reconstituted tobacco material. In particular, such a
material can include the extract of the invention (e.g., a
fire-cured tobacco extract) combined with an extracted tobacco pulp
(e.g., a fire-cured tobacco pulp), wherein the pulp has been
pre-treated to reduce benzo[a]pyrene concentration. For example,
the fire-cured tobacco extracted pulp can be pre-treated by
supercritical carbon dioxide extraction to reduce benzo[a]pyrene
concentration.
[0011] In another aspect, the invention provides a method of
producing a flavorful tobacco composition characterized by sensory
attributes associated with a fire-cured tobacco material and a
reduced benzo[a]pyrene concentration. The method includes the step
of mixing a fire-cured tobacco material having a first
benzo[a]pyrene concentration (e.g., at least about 100 ppb
benzo[a]pyrene) with a polar protic solvent (e.g., water or
co-solvent mixtures including water) to produce a slurry, the
slurry providing intimate contact between the fire-cured tobacco
material and the polar protic solvent. The method also includes
maintaining the slurry for a time and at a temperature sufficient
to form an extract comprising components of the cured tobacco
material soluble in the polar protic solvent, the extract
exhibiting a second benzo[a]pyrene concentration (e.g., less than
about 10 ppb benzo[a]pyrene) lower than the first benzo[a]pyrene
concentration. Thereafter, the extract is separated from a residual
pulp material comprising components of the fire-cured tobacco
material that are insoluble in the polar protic solvent. The method
typically also includes the step of utilizing the extract as a
flavorful tobacco composition by, for example, introducing the
separated extract into a tobacco product, which will often involve
applying the separated extract to a tobacco material or non-tobacco
plant material to form a treated material that can then be
incorporated into a tobacco product. In certain embodiments, the
extract is recombined with the extracted pulp following treatment
of the pulp to reduce benzo[a]pyrene content, such as a second
extraction of the pulp adapted to remove benzo[a]pyrene. For
example, the method can include treating the residual pulp material
with supercritical carbon dioxide to reduce benzo[a]pyrene
concentration and form a pulp material with reduced benzo[a]pyrene
concentration, and thereafter applying the separated extract to the
pulp material with reduced benzo[a]pyrene concentration to form the
treated material. If desired, the extract can be concentrated by
removing at least a portion of the solvent prior to incorporation
into a tobacco product.
[0012] In one particular embodiment, the invention provides a
process for preparing a composition suitable for use as a smokeless
tobacco composition, comprising: mixing a fire-cured tobacco
material having a first benzo[a]pyrene concentration with water to
produce an aqueous slurry, the slurry providing intimate contact
between the fire-cured tobacco material and the water; maintaining
the slurry for a time and at a temperature sufficient to form a
fire-cured tobacco extract comprising flavorful and aromatic
components of the fire-cured tobacco material soluble in water, the
aqueous fire-cured tobacco extract exhibiting a second
benzo[a]pyrene concentration lower than the first benzo[a]pyrene
concentration; separating the aqueous fire-cured tobacco extract
from a residual pulp material comprising components of the
fire-cured tobacco material that are insoluble in water; and mixing
the aqueous fire-cured tobacco extract with a tobacco or
non-tobacco plant material to form a smokeless tobacco
composition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to provide an understanding of embodiments of the
invention, reference is made to the appended drawings, which are
not necessarily drawn to scale, and in which reference numerals
refer to components of exemplary embodiments of the invention. The
drawings are exemplary only, and should not be construed as
limiting the invention.
[0014] FIG. 1 is an exploded perspective view of a smoking article
having the form of a cigarette, showing the smokable material, the
wrapping material components, and the filter element of the
cigarette; and
[0015] FIG. 2 is a cross-sectional view of a smokeless tobacco
product embodiment, taken across the width of the product, showing
an outer pouch filled with a smokeless tobacco composition of the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] The present invention now will be described more fully
hereinafter. This invention may, however, be embodied in many
different forms and should not be construed as limited to the
embodiments set forth herein; rather, these embodiments are
provided so that this disclosure will be thorough and complete, and
will fully convey the scope of the invention to those skilled in
the art. As used in this specification and the claims, the singular
forms "a," "an," and "the" include plural referents unless the
context clearly dictates otherwise. Reference to "dry weight
percent" or "dry weight basis" refers to weight on the basis of dry
ingredients (i.e., all ingredients except water).
[0017] The present invention provides a process for preparing a
flavorful tobacco composition it the form of a tobacco extract. In
certain embodiments, the extracts of the invention provide a
tobacco composition having advantageous sensory characteristics
combined with a reduced amount of certain compounds found in the
unextracted tobacco material. The process of the invention is
particularly useful for forming an extract of a fire-cured tobacco
material, although it can be applied to other tobacco materials
such as tobacco cured using other curing techniques (e.g.,
air-cured and/or flue-cured tobacco materials). See, for example,
techniques for curing tobacco set forth in US Pat. App. Pub. No.
2012/0037175 to Cantrell et al. and selected references cited
therein, which are incorporated by reference in their
entireties.
[0018] A "fire-cured tobacco" as used herein refers to a tobacco
material subjected to a fire curing process. In fire curing,
tobacco leaves are exposed to gaseous combustion products from an
open fire in the curing enclosure, typically for several weeks,
resulting in a distinctive smoky aroma and flavor. The distinctive
sensory characteristics of fire-cured tobacco can also be described
in some cases as woody, sweet, nutty, spicy, earthy, or sour. The
fire used for such curing processes is typically characterized as
low-burning or smoldering, meaning the fire is maintained in a
state that promotes smoke production. Fire cured tobaccos are
sometimes referred to as "dark fire" or "dark-fired" tobacco. See,
for example, the fire-curing processes and resulting tobacco
characteristics set forth in U.S. Pat. Nos. 7,650,891 and
7,650,892, both to Groves et al., and 7,757,697 to Thomas et al.,
all of which are incorporated by reference herein. See also, pages
164-182 of Tobacco Production, Chemistry and Technology, Davis et
al. (Eds.) (1999).
[0019] During fire curing, the tobacco material is involved in
intimate interaction and contact with the gaseous combustion
products of the fire in the curing enclosure, meaning the smoke
from the fire directly contacts the surface of the tobacco
material. This interaction between the smoke and the tobacco
results in chemical changes to the tobacco material that lead to
both the distinctive smoky aroma and flavor commonly associated
with fire-cured tobacco and other less desirable chemical changes
in the tobacco. The present invention provides a treatment process
that separates at least a portion of the components of the
fire-cured tobacco that provide the distinctive sensory
characteristics (i.e., smoky aroma and flavor) from at least a
portion of the components of the fire-cured tobacco that do not
contribute to a significant degree to the desired and distinctive
sensory characteristics. In other words, the invention provides a
separation process that selectively extracts components of
fire-cured tobacco that are desirable from a sensory standpoint,
but leaves behind at least a portion of those components that are
not necessary or desirable from a sensory standpoint.
[0020] When the process of the invention is applied to a fire-cured
tobacco material, an extract can be formed in certain embodiments
that is characterized by the desirable sensory attributes (e.g.,
smoky aroma and flavor) associated with fire-cured tobacco, but
with an altered chemistry profile that includes reduction in
certain polycyclic aromatic hydrocarbons typically found in
fire-cured tobacco, such as benzo[a]pyrene (i.e., BaP or B[a]p).
The structure of BaP is given below.
##STR00001##
[0021] Discussion of BaP and other polycyclic aromatic hydrocarbons
can be found in Gelboin, Physiological Reviews 60(4) (1980)
1107-1166; Phillips, Mutation Research 443 (1999) 139-147; Rodgman
and Perfetti, Contributions to Tobacco Research 22(1) (2006) 13-69;
Rodgman and Cook, Contributions to Tobacco Research 23(6) (2009)
384-410; and A. Rodgman and T. A. Perfetti, The Chemical Components
of Tobacco and Tobacco Smoke, CRC Press, Taylor and Francis Group,
Boca Raton, USA, (2009), all of which are incorporated by reference
herein.
[0022] Fire-cured tobacco extracts containing reduced levels of
polycyclic aromatic hydrocarbons enable the production of smoking
articles and smokeless tobacco compositions that exhibit the
desirable sensory characteristics of fire-cured tobacco, but with
reduced content of compounds not associated with the desirable
sensory properties, such as BaP. It is noted that sensory
characteristics of a composition can be evaluated using human
sensory panels as is understood in the art. Although the BaP
content can vary based on the particular tobacco plant and specific
fire-curing process employed, a typical BaP range for a fire-cured
tobacco is about 150 to about 800 parts by billion (ppb). In
certain embodiments of the invention, fire-cured tobacco extracts
can be formed with significantly lower BaP levels, such as less
than about 10 ppb, less than about 5 ppb, or even less than about 1
ppb. In other terms, the amount of BaP reduction that occurs during
the extraction process of the invention can be characterized as a
reduction of at least about 90 percent by weight of the content of
BaP in the original unextracted tobacco material, more often at
least about 95 percent or at least about 99 percent. It was
heretofore unknown that a fire-cured tobacco extract could be
formed that retains the distinctive sensory elements of such
tobaccos, but which exhibits a reduced content of certain less
desirable chemical compounds such as BaP. In one embodiment of the
method of the invention, the cured tobacco material (e.g.,
fire-cured tobacco) subjected to the extraction process has a BaP
concentration of at least about 100 ppb, more often at least about
150 ppb, or even at least about 200 ppb or at least about 300 ppb.
Following the extraction process, the separated extract exhibits a
much lower BaP concentration, such as a concentration of no more
than about 10 ppb, or no more than about 5 ppb, or no more than
about 1 ppb.
[0023] Various methods for determining BaP content are known in the
art. Typically, the method involves extracting BaP from a tobacco
material with methanol or a relatively non-polar solvent such as
hexane, cyclohexane or methylene chloride. The extract is then
filtered and analyzed using a High Performance Liquid
Chromatography (HPLC) method with fluorescence detection or a Gas
Chromatography-Mass Spectrometry (GC-MS) technique. Publications
directed to extraction and detection of BaP in tobacco or tobacco
products include Rodgman and Perfetti, Contributions to Tobacco
Research 22(1) (2006) 13-69; Risner, Beitr. Tabakforsch. Int 15(1)
(1991) 11-17; "Determination of Benzo[a]Pyrene in Whole Tobacco,"
Health Canada (1999) (published on the Health Canada website,
www.hc-sc.gc.ca), Aygun et al., International Journal of Food
Sciences and Nutrition 56(8) (2005) 581-585; and McNeill et al.,
Tob. Control 15 (2006) 64-67, all of which are incorporated by
reference herein.
[0024] The fire-cured tobacco used in the process of the invention
can include those tobacco materials commonly utilized in fire
curing, such as Narrow Leaf Madole, Improved Madole, Tom Rosson
Madole, Newton's VH Madole, Little Crittenden, Green Wood, Little
Wood, Small Stalk Black Mammoth, DT 508, DT 518, DT 592, KY 171, DF
911, DF 485, TN D94, TN D950, VA 309, and VA 359. However, any
tobacco material could be used without departing from the
invention, including those tobaccos commonly referred to as
flue-cured or Virginia (e.g., K326), burley, sun-cured (e.g.,
Indian Kurnool and Oriental tobaccos, including Katerini, Prelip,
Komotini, Xanthi and Yambol tobaccos), Maryland, dark, dark air
cured (e.g., Passanda, Cubano, Jatin and Bezuki tobaccos), light
air cured (e.g., North Wisconsin and Galpao tobaccos), Indian air
cured, Red Russian and Rustica tobaccos, as well as various other
rare or specialty tobaccos. Descriptions of various types of
tobaccos, growing practices and harvesting practices are set forth
in Tobacco Production, Chemistry and Technology, Davis et al.
(Eds.) (1999), which is incorporated herein by reference. Various
representative types of plants from the Nicotiana species are set
forth in Goodspeed, The Genus Nicotiana, (Chonica Botanica) (1954);
U.S. Pat. Nos. 4,660,577 to Sensabaugh, Jr. et al.; 5,387,416 to
White et al. and 7,025,066 to Lawson et al.; US Patent Appl. Pub.
Nos. 2006/0037623 to Lawrence, Jr. and 2008/0245377 to Marshall et
al.; each of which is incorporated herein by reference. In one
embodiment, tobacco varieties that are typically cured through
curing processes other than fire curing, such as flue-curing or
air-curing, are utilized in the extraction process of the
invention. If desired, such tobacco materials can be optionally
cured using a fire curing treatment instead of the traditional
curing process used for such materials.
[0025] The particular Nicotiana species of material used in the
invention could also vary. Of particular interest are N. alata, N.
arentsii, N. excelsior, N. forgetiana, N. glauca, N. glutinosa, N.
gossei, N. kawakamii, N. knightiana, N. langsdorffi, N. otophora,
N. setchelli, N. sylvestris, N. tomentosa, N. tomentosifothiis, N.
undulata, and N. x sanderae. Also of interest are N. africana, N.
amplexicaulis, N. benavidesii, N. bonariensis, N. debneyi, N.
longiflora, N. maritina, N. megalosiphon, N. occidentalis, N.
paniculata, N. plumbaginifolia, N. raimondii, N. rosulata, N.
rustica, N. simulans, N. stocktonii, N. suaveolens, N. tabacum, N.
umbratica, N. velutina, and N. wigandioides.
[0026] Other plants from the Nicotiana species include N. acaulis,
N. acuminata, N. attenuata, N. benthamiana, N. cavicola, N.
clevelandii, N. cordifolia, N. corymbosa, N. fragrans, N.
goodspeedii, N. linearis, N. miersii, N. nudicaulis, N.
obtusifolia, N. occidentalis subsp. Hersperis, N. pauciflora, N.
petunioides, N. quadrivalvis, N. repanda, N. rotundifolia, N.
solanifolia and N. spegazzinii. The Nicotiana species can be
derived using genetic-modification or crossbreeding techniques
(e.g., tobacco plants can be genetically engineered or crossbred to
increase or decrease production of certain components or to
otherwise change certain characteristics or attributes). See, for
example, the types of genetic modifications of plants set forth in
U.S. Pat. Nos. 5,539,093 to Fitzmaurice et al.; 5,668,295 to Wahab
et al.; 5,705,624 to Fitzmaurice et al.; 5,844,119 to Weigl;
6,730,832 to Dominguez et al.; 7,173,170 to Liu et al.; 7,208,659
to Colliver et al.; and 7,230,160 to Benning et al.; US Patent
Appl. Pub. No. 2006/0236434 to Conkling et al.; and PCT WO
2008/103935 to Nielsen et al.
[0027] At least a portion of the plant of the Nicotiana species can
be employed in an immature form (i.e., the plant, or at least one
portion of that plant, can be harvested before reaching a stage
normally regarded as ripe or mature, such as, for example, when the
tobacco plant is at the point of a sprout, is commencing leaf
formation, is commencing flowering, or the like). At least a
portion of the plant can be employed in a mature form (i.e., the
plant, or at least one portion of the plant can be harvested when
that plant (or plant portion) reaches a point that is traditionally
viewed as being ripe, over-ripe, or mature). As such, for example,
through the use of tobacco harvesting techniques conventionally
employed by farmers, Oriental tobacco plants can be harvested,
burley tobacco plants can be harvested, or Virginia tobacco leaves
can be harvested or primed by stalk position. The tobacco material
used in the invention can also be subjected to aging
conditions.
[0028] The plant can, in certain embodiments, be used in a green
form (e.g., tobacco can be used without being subjected to any
curing process). For example, tobacco in green form can be frozen,
subjected to irradiation, yellowed, dried, cooked (e.g., roasted,
fried or boiled), or otherwise subjected to storage or treatment
for later use. Such tobaccos can also can be subjected to aging
conditions.
[0029] According to the invention, a tobacco material of any of the
types noted above is harvested and subjected to a curing process,
such as a fire curing process. The resulting cured tobacco is then
subjected to an extraction process using certain polar protic
solvents, such as water, formic acid, acetic acid, dilute aqueous
solutions (e.g., solutions comprising greater than 70 weight
percent water and minor amounts of an alcohol or other co-solvent),
or mixtures thereof. The solvent typically has a dielectric
constant at room temperature of at least about 6, more often at
least about 30, and most often at least about 50.
[0030] Solvents having an aqueous character are particularly
useful, such as deionized water, distilled water, or tap water.
Such a solvent consists primarily of water, is normally greater
than 90 weight percent water, and can be essentially pure water in
certain circumstances. The extraction solvent can be a co-solvent
mixture, such as a mixture of water and minor amounts of one or
more solvents that are miscible therewith. An example of such a
co-solvent mixture is a solvent consisting of about 95 weight parts
water and about 5 weight parts ethanol. The extraction solvent also
can include water having substances such as pH adjusters (i.e.,
acids or bases) or pH buffers dissolved therein.
[0031] The extraction process involves placing the tobacco material
in intimate contact with the solvent at a suitable temperature and
for a suitable time period. The temperature of the extraction can
vary, but a typical temperature range is about room temperature to
about 110.degree. C., more often about 30.degree. C. to about
90.degree. C. In certain embodiments, the temperature of the
extraction step can be characterized as at least about 20.degree.
C., at least about 30.degree. C., at least about 50.degree. C., or
at least about 60.degree. C. It may be advisable to use a
relatively low temperature for the extraction process to prevent or
reduce volatilization of the flavorful or aromatic compounds that
are the primary targets of the extraction process. The time period
for the extraction step can vary, but is typically about 10 minutes
to about 24 hours, more often about 1 hour to about 12 hours. The
time period is not considered particularly critical to the
invention, although very short extraction time periods may not
result in extraction of a large proportion of the extractable
component of the tobacco material.
[0032] The amount of solvent used in the extraction process can
vary, but will typically be sufficient to place the tobacco
material in the form of a slurry. In other words, the solvent is
typically the predominate component of the tobacco/solvent mixture
and is often present in great excess compared to the tobacco
component. Weight ratios of solvent to tobacco material will
typically range from about 2:1 to about 20:1 (e.g., about 4:1 to
about 12:1), although other ratios (particularly even larger
ratios) could be used without departing from the invention. In
certain embodiments, the use of smaller amounts of water or other
solvent could be advantageous because less drying would be required
if the extract must be concentrated prior to use. Excessive drying
of the extract could lead to loss of certain volatile flavorful or
aromatic components of the extract, which could potentially result
in loss of some of the distinctive sensory characteristics of the
extract. Accordingly, use of weight ratios of solvent to tobacco
material of less than about 5:1 or less than about 4:1 during
extraction could be a useful technique to reduce or eliminate the
need to dry or otherwise concentrate the resulting extract. In such
an embodiment, the extract would be expected to exhibit a
relatively high viscosity and can be applied to certain tobacco
products without further processing.
[0033] The manner by which the solvent and the tobacco material are
combined for extraction may vary. The solvent and tobacco material
can be contacted, combined, or mixed together in conical-type
blenders, mixing drums, ribbon blenders, or the like. The mixture
can be agitated or subjected to a grinding action during the
extraction step. Following extraction, the residual pulp is removed
from the liquid extraction product using any method known in the
art, such as filtration or centrifugation. The tobacco material is
typically in shredded or particulate form during extraction, such
as tobacco particles having a particle size in the range of about
0.5 mm to about 25 mm. The vessel in which the tobacco material and
the solvent are mixed is typically vented such that the extraction
proceeds at atmospheric pressure, or if desired, a pressurized
vessel can be used. Following the extraction process, a tobacco
extract is provided by separating the solvent-insoluble pulp
material from the solvent and the solvent-soluble or dispersible
tobacco components dissolved or dispersed therein.
[0034] Equipment, types of solvents, and techniques for obtaining
extracts of tobacco, including in some cases equipment, solvents,
and techniques that can be used or suitably modified for use in the
method of the invention, are described in U.S. Pat. Nos. 4,144,895
to Fiore; 4,150,677 to Osborne, Jr. et al.; 4,267,847 to Reid;
4,289,147 to Wildman et al.; 4,351,346 to Brummer et al.; 4,359,059
to Brummer et al.; 4,506,682 to Muller; 4,589,428 to Keritsis;
4,605,016 to Soga et al.; 4,716,911 to Poulose et al.; 4,727,889 to
Niven, Jr. et al.; 4,887,618 to Bernasek et al.; 4,941,484 to Clapp
et al.; 4,967,771 to Fagg et al.; 4,986,286 to Roberts et al.;
5,005,593 to Fagg et al.; 5,018,540 to Grubbs et al.; 5,060,669 to
White et al.; 5,065,775 to Fagg; 5,074,319 to White et al.;
5,099,862 to White et al.; 5,121,757 to White et al.; 5,131,414 to
Fagg; 5,131,415 to Munoz et al.; 5,148,819 to Fagg; 5,197,494 to
Kramer; 5,230,354 to Smith et al.; 5,234,008 to Fagg; 5,243,999 to
Smith; 5,301,694 to Raymond et al.; 5,318,050 to Gonzalez-Parra et
al.; 5,343,879 to Teague; 5,360,022 to Newton; 5,435,325 to Clapp
et al.; 5,445,169 to Brinkley et al.; 6,131,584 to Lauterbach;
6,298,859 to Kierulff et al.; 6,772,767 to Mua et al.; and
7,337,782 to Thompson, all of which are incorporated by reference
herein.
[0035] Following separation of the extract from the pulp, both the
extract and the residual pulp can be further processed if desired.
For example, the extract can be processed in a manner adapted to
concentrate the dissolved or dispersed components of the tobacco
material by removing at least a portion of the solvent. Various
methods of solvent removal can be used, such as heat treatment to
evaporate the solvent (e.g., with an evaporator and condenser
arrangement), reverse osmosis membrane treatment, spray drying or
freeze drying. In the case of an aqueous extract, the concentration
step could simply entail heating the extract to a temperature above
the boiling point of water in a vented vessel. The extract could
also be subjected to other treatment processes designed to change
the chemical composition of the extract, such as reaction with
acids or bases, ultrafiltration to remove high molecular weight
components, treatment to remove additional components of the
extract such as tobacco-specific nitrosamines (TSNAs), or the
like.
[0036] In one specific embodiment, the essentially BaP-free extract
is processed to reduce the concentration of TSNAs in the extract.
Exemplary TSNA compounds include N-nitrosonornicotine (NNN),
4-methyl-N-nitrosamino-1-(3-pyridyl)-1-butanone (NNK),
N-nitrosoanatabine (NAT),
4-methyl-N-nitrosamino-1-(3-pyridyl)-1-butanol (NNAL), and
N-nitrosoanabasine (NAB). The method for reducing the TSNA level
can vary. In one method, a preparative HPLC technique is used where
the extract is passed through a HPLC column and the portion of the
extract eluting from the column at the known retention time for
TSNA compounds is simply discarded. In another method, the extract
is passed through a molecularly imprinted polymer (MIP) material
having functional groups that selectively sorb TSNA compounds.
Exemplary TSNA-specific MIP materials include polymer sorbents
offered by Sigma-Aldrich Company under the brand name SupelMIP.RTM.
SPE and Affinilute.TM. MIP materials available from Biotage AB. The
polymeric sorbent can be contacted with the extract to selectively
sorb the TSNA compounds using a variety of techniques such as
packing a column with the sorbent and passing the extract
therethrough. In certain embodiments, the TSNA level of the extract
can be reduced from greater than 1,000 ppb or even greater than
2,000 ppb to less than about 400 ppb or less than about 300 ppb or
less than about 200 ppb. In some cases, the TSNA level can be
reduced to less than about 100 ppb or less than about 50 ppb.
[0037] In one embodiment, the residual tobacco pulp produced in the
extraction process can be treated to reduce benzo[a]pyrene
concentration in order to prepare the pulp for recombination with
the extract to form a reconstituted tobacco material exhibiting a
reduced benzo[a]pyrene concentration. For example, the pulp could
be subjected to a second extraction process using supercritical
carbon dioxide or another suitable solvent (e.g., relatively
non-polar solvents such as hexane, cyclohexane or methylene
chloride) such that the benzo[a]pyrene dissolves in the solvent to
facilitate removal from the pulp. Carbon dioxide extraction
processes that could be used in the present invention, or suitably
modified for use in the present invention, are set forth in, for
example, U.S. Pat. Nos. 4,153,063 to Roselius et al.; 4,506,682 to
Muller; 4,714,617 to Gahrs; 4,727,889 to Niven, Jr. et al.;
5,018,540 to Grubbs et al.; and 5,435,325 to Clapp et al., all of
which are incorporated by reference herein.
[0038] In certain embodiments, the tobacco pulp is subjected to
supercritical CO.sub.2 extraction as further described herein.
Generally, supercritical fluid extraction adds supercritical
CO.sub.2 to tobacco pulp to facilitate the removal of certain
components (e.g., B[a]p and TSNA) from the tobacco pulp. The
extraction can be conducted using any type of equipment capable of
bringing the tobacco into contact with supercritical CO.sub.2. For
example, in some specific embodiments, a supercritical fluid
extraction system, such as available from Jasco, Inc. (Easton, Md.)
can be used. In certain embodiments, pure supercritical CO.sub.2 is
the extraction medium; however, in certain embodiments, it may be
possible to use an extraction medium that comprises one or more
components in addition to supercritical CO.sub.2. The extraction
process may utilize a back flow medium (e.g., methanol) downstream
to trap compounds that are extracted (i.e., removed) from the
tobacco material.
[0039] Various parameters of the supercritical CO.sub.2 extraction
process can be varied. In certain embodiments, altering one or more
of these parameters can alter the efficiency of the extraction
process. For example, the pressure, temperature, CO.sub.2 flow
rate, and total extraction time can be varied. For example, in
certain embodiments, a pressure of about 10 MPa or greater, and
more preferably a pressure of about 20 MPa or greater is used. For
example, in some embodiments, a pressure of between about 5 MPa and
about 40 MPa (e.g., between about 10 MPa and about 40 MPa or
between about 10 MPa and about 30 MPa) is used. In certain
embodiments, a temperature of about 40.degree. C. or greater is
used, and more preferably, a temperature of about 60.degree. C. or
greater is used. For example, in some embodiments, a temperature of
between about 30.degree. C. and about 70.degree. C. is used (e.g.,
between about 40.degree. C. and about 60.degree. C.). In certain
embodiments, a flow rate of about 5 mL/min or greater is used, and
more preferably, a flow rate of about 10 mL/min or greater is used.
For example, in some embodiments, a flow rate of between about 4
mL/min and about 15 mL/min (e.g., between about 5 mL/min and about
10 mL/min) is used.
[0040] In certain embodiments, the total extraction time is about
10 minutes or more, about 15 minutes or more, or about 30 minutes
or more. Typically, total extraction times of about 15 minutes or
more result in good removal of both B[a]p and TSNA (e.g., greater
than about 50% removal of both B[a].sub.p and TSNA). In certain
embodiments, total extraction times of about 30 minutes or more
provided even greater removal of both B[a]p and TSNA. It is noted
that, in some embodiments, higher or lower temperatures, higher or
lower flow rates, and/or higher or lower total extraction times can
be utilized to provide good results (i.e., a significant decrease
in the concentration of B[a]p and/or TSNA).
[0041] In certain embodiments wherein the tobacco pulp treated by
supercritical CO.sub.2 extraction has been previously subjected to
an aqueous extraction, the resulting treated pulp can be
characterized as a "double-extracted" tobacco pulp. A
double-extracted pulp thus comprises a pulp wherein aqueous
components have been removed via aqueous extraction and additional
components have been removed via supercritical CO.sub.2
extraction.
[0042] The supercritical CO.sub.2 extraction process generally
results in a reduction in the amount of B[a]p and/or the amount of
TSNA present in the tobacco material. In certain embodiments, the
supercritical CO.sub.2 extraction can provide a reduction in B[a]p
of about 5% or more, about 10% or more, about 20% or more, about
30% or more, about 40% or more, about 50% or more, about 60% or
more, about 70% or more, or about 80% or more as compared with
tobacco that has not been treated by supercritical CO.sub.2
extraction. Generally, tobacco that has not been treated by
supercritical CO.sub.2 extraction can have a B[a]p level that may
be greater than about 50 ng/g, greater than about 100 ng/g, greater
than about 150 ng/g, or greater than about 200 ng/g. In certain
embodiments, tobacco pulp that has been treated by supercritical
CO.sub.2 extraction can be characterized as having less than about
150 ng/g, less than about 100 ng/g, less than about 80 ng/g, or
less than about 50 ng/g. In certain embodiments, the supercritical
CO.sub.2 extraction can provide a reduction in TSNA of about 5% or
more, about 10% or more, about 20% or more, about 30% or more,
about 40% or more, about 50% or more, about 60% or more, about 70%
or more, or about 80% or more as compared with tobacco that has not
been treated by supercritical CO.sub.2 extraction. Generally,
tobacco that has not been treated by supercritical CO.sub.2
extraction can have a TSNA level that may be greater than about
2,500 ng/g, greater than about 5,000 ng/g, greater than about 7,500
ng/g, or greater than about 10,000 ng/g. In certain embodiments,
tobacco pulp that has been treated by supercritical CO.sub.2
extraction can be characterized as having less than about 5,000
ng/g, less than about 7,500 ng/g, less than about 5,000 ng/g, less
than about 2,000 ng/g, or less than about 1,000 ng/g.
[0043] Thereafter, a reconstituted tobacco material can be formed
by adding the extract from the original extraction process back to
the pre-treated pulp (e.g., the pulp that has been treated by
supercritical carbon dioxide extraction). Exemplary manners and
methods for providing a reconstituted tobacco sheet, including
casting and paper-making techniques, are set forth in U.S. Pat.
Nos. 4,674,519 to Keritsis et al.; 4,941,484 to Clapp et al.;
4,987,906 to Young et al.; 4,972,854 to Kiernan et al.; 5,099,864
to Young et al.; 5,143,097 to Sohn et al.; 5,159,942 to Brinkley et
al.; 5,322,076 to Brinkley et al.; 5,339,838 to Young et al.;
5,377,698 to Litzinger et al.; 5,501,237 to Young; and 6,216,707 to
Kumar; each of which is incorporated herein by reference. See also
the tobacco extraction and reconstituted tobacco processes set
forth in U.S. Pat. Nos. 5,065,775 to Fagg and 5,360,022 to Newton
et al., which are incorporated herein by reference.
[0044] The tobacco material that is subjected to the extraction
process can also be subjected to pre-treatment processes adapted to
modify the sensory, chemical or physical properties of the
material. For example, it may be desirable to pre-treat the tobacco
material to remove components of the tobacco that may generate
negative sensory off-notes so that those components are not
extracted in the process of the invention. Exemplary pre-treatment
processes for the tobacco material include fermentation, bleaching,
and the like.
[0045] In some embodiments of the invention, it is advantageous to
pre-treat a fire-cured tobacco to change the sensory
characteristics in a manner that can be characterized as generating
a milder flavor or aroma. One exemplary process that can generate a
milder flavor or aroma in certain tobacco materials, such as a
fire-cured tobacco, is fermentation. During fermentation, bacteria
interact with the tobacco material in a moist,
temperature-controlled and pH-controlled environment to alter the
chemical profile of the tobacco material. Commercially available
fermented tobacco materials could be used in the extraction process
of the invention, such as moist snuff tobacco compositions marketed
as GRIZZLY or KODIAK smokeless tobacco. Tobacco fermentation
processes are described, for example, in Giacomo et al., Appl.
Environ. Microbiol. 73(3) (2007) 825-837; U.S. Pat. No. 5,372,149
to Roth et al.; and in Tobacco Production, Chemistry and
Technology, Davis et al. (Eds.) (1999), all of which are
incorporated by reference herein.
[0046] The tobacco extract can be utilized as a flavorful tobacco
composition that can be incorporated into a variety of tobacco
products. In particular, fire-cured tobacco extracts of the
invention can impart the distinctive sensory characteristics of
fire-cured tobacco to various tobacco products without introducing
significant amounts of certain chemical compounds associated with
unextracted or whole fire-cured tobaccos, such as BaP. The tobacco
extract (e.g., the aqueous tobacco extract) can be employed in a
variety of forms. For example, the tobacco extract can be isolated
in an essentially solvent free form, such as can be obtained as a
result of the use of a spray drying or freeze drying process, or
other similar types of processing steps. Alternatively, the aqueous
tobacco extract can be employed in a liquid faun, and as such, the
content of tobacco solubles within the liquid solvent can be
controlled by selection of the amount of solvent employed for
extraction, concentration of the liquid tobacco extract by removal
of solvent, addition of solvent to dilute the liquid tobacco
extract, or the like.
[0047] The tobacco product to which the extracts of the invention
are added can vary, and include any product configured or adapted
to deliver tobacco or some component thereof to the user of the
product. Exemplary tobacco products include smoking articles (e.g.,
cigarettes), smokeless tobacco products, and aerosol-generating
devices that contain a tobacco material or other plant material
that is not combusted during use.
[0048] Typically, the incorporation of the extract of the invention
into a tobacco product will involve use of a tobacco material or
non-tobacco plant material as a carrier for the extract, such as by
absorbing the extract into the tobacco or other plant material or
otherwise associating the extract with the carrier material, such
as by adhesion of spray-dried particles of the extract on the
carrier material. The types of tobacco that can serves as the
carrier for the extracts of the invention can vary, and can include
any of the tobacco types discussed herein, including various cured
tobacco materials (e.g., flue-cured or air-cured tobaccos) or
portions thereof (e.g., tobacco lamina or tobacco stems).
[0049] In one embodiment, the tobacco to which the extract is
applied is a fermented tobacco material, and the extract is applied
either before, during, or after the fermentation process. The
tobacco material to which the extract is applied will typically be
characterized as having a relatively low BaP level, such as many
air-cured or flue-cured tobacco materials or tobacco materials
pre-treated to reduce BaP level. The physical configuration of the
tobacco material to which the extract is added can also vary, and
can include tobacco materials in shredded or particulate faun, or
in the form of a sheet (e.g., reconstituted tobacco sheets) or in
whole leaf form. The dry weight ratio of tobacco material to
extract of the invention can vary, but is typically about 4:1 to
about 1:4, about 2:1 to about 1:2, and often about 1.5:1 to about
1:1.5.
[0050] In one embodiment, the extract of the invention is used as a
flavorful tobacco composition in the manufacture of smoking
articles. For example, the extract prepared in accordance with the
present invention can be mixed with casing materials and applied to
tobacco as a casing ingredient (e.g., using the types of methods
set forth in U.S. Pat. No. 4,819,668 to Shelar, which is
incorporated herein by reference), incorporated into smoking
articles as a top dressing ingredient, or incorporated into
reconstituted tobacco materials (e.g., using the types of tobacco
reconstitution processes generally set forth in U.S. Pat. Nos.
5,143,097 to Sohn; 5,159,942 to Brinkley et al.; 5,598,868 to
Jakob; 5,715,844 to Young; 5,724,998 to Gellatly; and 6,216,706 to
Kumar, which are incorporated herein by reference). Still further,
the extracts of the invention can be incorporated into a cigarette
filter (e.g., in the filter plug, plug wrap, or tipping paper) or
incorporated into cigarette wrapping paper, preferably on the
inside surface, during the cigarette manufacturing process.
[0051] Referring to FIG. 1, there is shown a smoking article 10 in
the form of a cigarette and possessing certain representative
components of a smoking article that can contain the extract of the
present invention. The cigarette 10 includes a generally
cylindrical rod 12 of a charge or roll of smokable filler material
(e.g., about 0.3 to about 1.0 g of smokable filler material such as
tobacco material) contained in a circumscribing wrapping material
16. The rod 12 is conventionally referred to as a "tobacco rod."
The ends of the tobacco rod 12 are open to expose the smokable
filler material. The cigarette 10 is shown as having one optional
band 22 (e.g., a printed coating including a film-forming agent,
such as starch, ethylcellulose, or sodium alginate) applied to the
wrapping material 16, and that band circumscribes the cigarette rod
in a direction transverse to the longitudinal axis of the
cigarette. The band 22 can be printed on the inner surface of the
wrapping material (i.e., facing the smokable filler material), or
less preferably, on the outer surface of the wrapping material.
[0052] At one end of the tobacco rod 12 is the lighting end 18, and
at the mouth end 20 is positioned a filter element 26. The filter
element 26 positioned adjacent one end of the tobacco rod 12 such
that the filter element and tobacco rod are axially aligned in an
end-to-end relationship, preferably abutting one another. Filter
element 26 may have a generally cylindrical shape, and the diameter
thereof may be essentially equal to the diameter of the tobacco
rod. The ends of the filter element 26 permit the passage of air
and smoke therethrough.
[0053] A ventilated or air diluted smoking article can be provided
with an optional air dilution means, such as a series of
perforations 30, each of which extend through the tipping material
and plug wrap. The optional perforations 30 can be made by various
techniques known to those of ordinary skill in the art, such as
laser perforation techniques. Alternatively, so-called off-line air
dilution techniques can be used (e.g., through the use of porous
paper plug wrap and pre-perforated tipping paper).
[0054] The extracts of the invention can also be incorporated into
aerosol-generating devices that contain tobacco material (or some
portion or component thereof) that is not intended to be combusted
during use. Exemplary references that describe smoking articles of
a type that generate flavored vapor, visible aerosol, or a mixture
of flavored vapor and visible aerosol, include U.S. Pat. Nos.
3,258,015 to Ellis et al.; 3,356,094 to Ellis et al.; 3,516,417 to
Moses; 4,347,855 to Lanzellotti et al.; 4,340,072 to Bolt et al.;
4,391,285 to Burnett et al.; 4,917,121 to Riehl et al.; 4,924,886
to Litzinger; and 5,060,676 to Hearn et al., all of which are
incorporated by reference herein. Many of these types of smoking
articles employ a combustible fuel source that is burned to provide
an aerosol and/or to heat an aerosol-forming material. See, for
example, U.S. Pat. Nos. 4,756,318 to Clearman et al.; 4,714,082 to
Banerjee et al.; 4,771,795 to White et al.; 4,793,365 to Sensabaugh
et al.; 4,917,128 to Clearman et al.; 4,961,438 to Korte; 4,966,171
to Serrano et al.; 4,969,476 to Bale et al.; 4,991,606 to Serrano
et al.; 5,020,548 to Farrier et al.; 5,033,483 to Clearman et al.;
5,040,551 to Schlatter et al.; 5,050,621 to Creighton et al.;
5,065,776 to Lawson; 5,076,296 to Nystrom et al.; 5,076,297 to
Farrier et al.; 5,099,861 to Clearman et al.; 5,105,835 to Drewett
et al.; 5,105,837 to Barnes et al.; 5,115,820 to Hauser et al.;
5,148,821 to Best et al.; 5,159,940 to Hayward et al.; 5,178,167 to
Riggs et al.; 5,183,062 to Clearman et al.; 5,211,684 to Shannon et
al.; 5,240,014 to Deevi et al.; 5,240,016 to Nichols et al.;
5,345,955 to Clearman et al.; 5,551,451 to Riggs et al.; 5,595,577
to Bensalem et al.; 5,819,751 to Barnes et al.; 6,089,857 to
Matsuura et al.; 6,095,152 to Beven et al; 6,578,584 to Beven; and
6,730,832 to Dominguez; which are incorporated herein by reference.
Furthermore, certain types of cigarettes that employ carbonaceous
fuel elements have been commercially marketed under the brand names
"Premier" and "Eclipse" by R. J. Reynolds Tobacco Company. See, for
example, those types of cigarettes described in Chemical and
Biological Studies on New Cigarette Prototypes that Heat Instead of
Burn Tobacco, R. J. Reynolds Tobacco Company Monograph (1988) and
Inhalation Toxicology, 12:5, p. 1-58 (2000). Addition types of
aerosol-generating devices are described in U.S. Pat. No. 7,726,320
to Robinson et al. and US Pat. Appl. Pub. Nos. 2006/0196518 and
2007/0267031, both to Hon, all of which are incorporated by
reference herein.
[0055] The extracts of the invention can be incorporated into
smokeless tobacco products, such as loose moist snuff (e.g., snus),
loose dry snuff, chewing tobacco, pelletized tobacco pieces (e.g.,
having the shapes of pills, tablets, spheres, coins, beads, obloids
or beans), extruded or formed tobacco strips, pieces, rods,
cylinders or sticks, finely divided ground powders, finely divided
or milled agglomerates of powdered pieces and components,
flake-like pieces, molded processed tobacco pieces, pieces of
tobacco-containing gum, rolls of tape-like films, readily
water-dissolvable or water-dispersible films or strips (e.g., US
Pat. App. Pub. No. 2006/0198873 to Chan et al.), or capsule-like
materials possessing an outer shell (e.g., a pliable or hard outer
shell that can be clear, colorless, translucent or highly colored
in nature) and an inner region possessing tobacco or tobacco flavor
(e.g., a Newtonian fluid or a thixotropic fluid incorporating
tobacco of some form). Various types of smokeless tobacco products
are set forth in U.S. Pat. Nos. 1,376,586 to Schwartz; 3,696,917 to
Levi; 4,513,756 to Pittman et al.; 4,528,993 to Sensabaugh, Jr. et
al.; 4,624,269 to Story et al.; 4,987,907 to Townsend; 5,092,352 to
Sprinkle, I I I et al.; and 5,387,416 to White et al.; US Pat. App.
Pub. Nos. 2005/0244521 to Strickland et al. and 2008/0196730 to
Engstrom et al.; PCT WO 04/095959 to Arnarp et al.; PCT WO
05/063060 to Atchley et al.; PCT WO 05/016036 to Bjorkholm; and PCT
WO 05/041699 to Quinter et al., each of which is incorporated
herein by reference. See also, the types of smokeless tobacco
formulations, ingredients, and processing methodologies set forth
in U.S. Pat. Nos. 6,953,040 to Atchley et al. and 7,032,601 to
Atchley et al.; US Pat. Appl. Pub. Nos. 2002/0162562 to Williams;
2002/0162563 to Williams; 2003/0070687 to Atchley et al.;
2004/0020503 to Williams, 2005/0178398 to Breslin et al.;
2006/0191548 to Strickland et al.; 2007/0062549 to Holton, Jr. et
al.; 2007/0186941 to Holton, Jr. et al.; 2007/0186942 to Strickland
et al.; 2008/0029110 to Dube et al.; 2008/0029116 to Robinson et
al.; 2008/0029117 to Mua et al.; 2008/0173317 to Robinson et al.;
2008/0209586 to Neilsen et al.; 2010/0018541 to Gerardi et al.;
2010/0018540 to Doolittle et al.; and 2010/0116281 to Marshall et
al., each of which is incorporated herein by reference.
[0056] Referring to FIG. 2, a representative snus type of tobacco
product comprising the extract of the present invention is shown.
In particular, FIG. 2 illustrates a smokeless tobacco product 40
having a water-permeable outer pouch 42 containing a smokeless
tobacco composition 44, wherein the tobacco composition includes a
shredded or particulate tobacco material serving as a carrier for
the extract of the invention.
[0057] Many exemplary smokeless tobacco compositions that can
benefit from use of the extract of the invention comprise shredded
or particulate tobacco material that can serve as a carrier for the
flavorful extract of the invention. The smokeless tobacco
compositions of the invention can also include a water-soluble
polymeric binder material and optionally other ingredients that
provide a dissolvable composition that will slowly disintegrate in
the oral cavity during use. In certain embodiments, the smokeless
tobacco composition can include lipid components that provide a
meltable composition that melts (as opposed to merely dissolving)
in the oral cavity, such as compositions set forth in U.S.
application Ser. No. 12/854,342 to Cantrell et al., filed Aug. 11,
2010, and which is incorporated by reference herein.
[0058] In one particular smokeless tobacco product embodiment, the
extract of the invention is added to a non-tobacco plant material,
such as a plant material selected from potato, beet (e.g., sugar
beet), grain, pea, apple, and the like. The non-tobacco plant
material can be used in a processed faun. In certain preferred
embodiments, the non-tobacco plant material can be used in an
extracted form, and as such, at least a portion of certain solvent
soluble components are removed from that material. The non-tobacco
extracted plant material is typically highly extracted, meaning a
substantial amount of the aqueous soluble portion of the plant
material has been removed. For example, a water-extracted pulp can
be obtained by extracting significant amounts of water soluble
components from the plant material. For example, certain
water-extracted plant materials can comprise less than about 20
weight percent, and often less than about 10 weight percent water
soluble components; and depending upon processing conditions,
certain water-extracted plant materials can be virtually free of
water soluble components (e.g., less than about 1 weight percent
water soluble components). One preferred water-extracted plant
material is water extracted sugar beet pulp (e.g., water extracted
sugar beet leaf pulp). The extracted non-tobacco plant material is
typically used in a form that can be described as shredded, ground,
granulated, fine particulate, or powder form. The dry weight ratio
of non-tobacco plant material to tobacco extract of the invention
is typically about 4:1 to about 1:4, about 2:1 to about 1:2, and
often about 1.5:1 to about 1:1.5. Smokeless tobacco products of
this type are set forth in U.S. application Ser. No. 12/756,656 to
Beeson et al, filed Apr. 8, 2010, which is incorporated by
reference herein.
[0059] Further additives can be admixed with, or otherwise
incorporated within, the smokeless tobacco compositions according
to the invention. The additives can be artificial, or can be
obtained or derived from herbal or biological sources. Exemplary
types of additives include salts (e.g., sodium chloride, potassium
chloride, sodium citrate, potassium citrate, sodium acetate,
potassium acetate, and the like), natural sweeteners (e.g.,
fructose, sucrose, glucose, maltose, vanillin, ethylvanillin
glucoside, mannose, galactose, lactose, and the like), artificial
sweeteners (e.g., sucralose, saccharin, aspartame, acesulfame K,
neotame and the like), organic and inorganic fillers (e.g., grains,
processed grains, puffed grains, maltodextrin, dextrose, calcium
carbonate, calcium phosphate, corn starch, lactose, manitol,
xylitol, sorbitol, finely divided cellulose, and the like), binders
(e.g., povidone, sodium carboxymethylcellulose and other modified
cellulosic types of binders, sodium alginate, xanthan gum,
starch-based binders, gum arabic, lecithin, and the like), pH
adjusters or buffering agents (e.g., metal hydroxides, preferably
alkali metal hydroxides such as sodium hydroxide and potassium
hydroxide, and other alkali metal buffers such as metal carbonates,
preferably potassium carbonate or sodium carbonate, or metal
bicarbonates such as sodium bicarbonate, and the like), colorants
(e.g., dyes and pigments, including caramel coloring and titanium
dioxide, and the like), humectants (e.g., glycerin, propylene
glycol, and the like), oral care additives (e.g., thyme oil,
eucalyptus oil, and zinc), preservatives (e.g., potassium sorbate,
and the like), syrups (e.g., honey, high fructose corn syrup, and
the like), disintegration aids (e.g., microcrystalline cellulose,
croscarmellose sodium, crospovidone, sodium starch glycolate,
pregelatinized corn starch, and the like), flavorant and flavoring
mixtures, antioxidants, and mixtures thereof. If desired, the
additive can be microencapsulated as set forth in US Patent Appl.
Pub. No. 2008/0029110 to Dube et al., which is incorporated by
reference herein.
[0060] The amount of tobacco extract that is added to a tobacco
composition or tobacco product can vary, and will depend in part on
the desired function of the extract, the chemical makeup of the
extract, and the type of tobacco composition or product to which
the extract is added. Unless otherwise indicated herein, the amount
added to a tobacco product will typically not exceed about 25
weight percent based on the total dry weight of the tobacco
composition to which the extract is added. When the extract is
employed within a smoking article, the amount of extract will
typically be at least about 5 ppm, generally at least about 10 ppm,
and often at least about 100 ppm, based on the total dry weight of
the tobacco material within the smoking article; but will typically
be less than about 5 percent, generally less than about 2 percent,
and often less than about 1 percent, based on the total dry weight
of the tobacco material within the smoking article. When the
extract is employed within a smokeless tobacco product, the amount
of extract will typically be at least about 5 ppm, generally at
least about 10 ppm, and often at least about 100 ppm, based on the
total dry weight of the tobacco material within the smokeless
tobacco product; but will typically be less than about 10 percent,
generally less than about 5 percent, and often less than about 1
percent, based on the total dry weight of the tobacco material
within the smokeless tobacco product.
EXPERIMENTAL
[0061] Aspects of the present invention are more fully illustrated
by the following examples, which are set forth to illustrate
certain aspects of the present invention and are not to be
construed as limiting thereof. Unless otherwise noted, all parts
and percentages are by weight.
Example 1
[0062] A fire-cured tobacco is extracted using water. A typical
extraction process combines milled tobacco (e.g., 100% pass 0.250
inch screen) with water at a ratio of 8 parts water to 1 part
tobacco at a temperature of about 72.degree. C. The mixture is
agitated for one hour and the suspended solids removed by
filtration using a 5 micron filter bag. The resulting tobacco
extract retains the aroma and sensory characteristics of the
fire-cured tobacco. The original fire-cured tobacco has a BaP level
prior to extraction of about 150 to 800 parts per billion and the
separated liquid extract has a BaP level of less than about 1 part
per billion.
Example 2
[0063] An air-cured tobacco is subjected to the same extraction
process as set forth in Example 1. The original air-cured tobacco
has a BaP level prior to extraction of about 10-150 parts per
billion and the separated liquid extract has a BaP level of less
than about 1 part per billion.
Example 3
[0064] Ground fire-cured tobacco having a moisture content of 10%
is extracted using supercritical CO.sub.2. An exemplary extraction
process employs a Jasco supercritical fluid extraction system,
comprising preparation pumps, column thermostat, photodiode array
detector, HPLC pump, automatic back pressure regulator, and 6-valve
change unit capable of collecting samples in a time sequence manner
during a single extraction run. A stainless steel pressure
extraction vessel is located inside the column thermostat, with a
pressure limit of 40 MPa. The extractions are conducted using 100%
CO.sub.2 and methanol is used as the back flow to trap extracted
compounds.
[0065] The pressure, temperature, and CO.sub.2 flow rate with which
the extraction is conducted are varied to assess the effects of
each on the removal of B[a]p and TSNA from the tobacco. Pressure is
held at 10, 20, or 30 MPa, temperature is held at either 40.degree.
C. or 60.degree. C., and CO.sub.2 flow rate is set at 5 or 10
mL/min. The resulting solid residues are extracted with hexanes and
subjected to liquid chromatography to evaluate B[a]p and TSNA
concentrations of the extracted material as compared with those of
unextracted tobacco.
[0066] At higher temperatures and lower pressures, only a small
decrease in B[a]p (.about.5% reduction) and TSNA (less than about
20% reduction) are observed. Increasing the pressure at which the
extraction is conducted provides comparable results. The highest
TSNA reduction is obtained using moderate (20 MPa) pressure, a
temperature of 60.degree. C., and a flow rate of 10 mL/min. The
highest B[a]p reduction (62% reduction) is obtained using a
pressure of 30 MPa, a temperature of 60.degree. C., and a flow rate
of 10 mL/min.
Example 4
[0067] Water-extracted fire cured tobacco pulp having a moisture
content of 11% is extracted using supercritical CO.sub.2 using the
method described in Example 3. The CO.sub.2 flow rate is set at 10
mL/min and the temperature is set at 40.degree. C. or 60.degree. C.
and pressure is set at 10, 20, or 30 MPa to evaluate the effect of
temperature and pressure on the removal of B[a]p and TSNA from
water-extracted fire-cured tobacco.
[0068] As temperature and pressure are increased, more B[a]p and
TSNA are removed from the tobacco. However, at a pressure of 10
MPa, increasing the temperature from 40.degree. C. to 60.degree. C.
does not have much of an effect on the removal of B[a]p or TSNA
from water-extracted fire-cured tobacco. The highest TSNA reduction
(63%) is obtained using a pressure of 30 MPa, and a temperature of
60.degree. C. The highest B[a]p reduction (46% and 47%,
respectively) is obtained using a pressure of 30 MPa with a
temperature of either 40.degree. C. or 60.degree. C.
Example 5
[0069] Ground fire-cured tobacco with a moisture content of 10% is
extracted using supercritical CO.sub.2 as described in Example 3.
The pressure is held at 20 MPa, the temperature is held at
40.degree. C., and the flow rate is held at 10 mL/min CO.sub.2. The
extraction time is varied to assess the effect of extraction time
on the removal of B[a]p and TSNA. Extractions are conducted over
periods of 15 minutes, 30 minutes, 45 minutes, 60 minutes, and 120
minutes. The decrease in B[a]p and TSNA observed with the sample
that was subjected to extraction for 30 minutes is comparable to
that observed with samples subjected to extraction for longer than
30 minutes; therefore, 30 minutes is selected as the extraction
duration for remaining experiments.
[0070] Water-extracted fire-cured tobacco pulp with a moisture
content of 11% is similarly extracted using various extraction
times. Again, an extraction time of 30 minutes results in
sufficient removal of both B[a]p and TSNA.
Example 6
[0071] Various fire-cured and water-extracted fire cured tobacco
pulp samples are extracted using supercritical CO.sub.2 as
described in Example 3. The moisture content of the tobacco samples
prior to extraction is varied to evaluate the effect of moisture on
the removal of B[a]p and TSNA. The pressure is held at 20 MPa, the
temperature is held at 40.degree. C., the flow rate is 10 mL/min
CO.sub.2, and the run time is 30 minutes. Varying levels of
moisture are added to tobacco samples prior to extraction, to give
fire-cured tobacco samples having 10%, 16%, 21%, 25%, and 31%
moisture content and water-extracted fire-cured tobacco samples
having 10%, 11%, 16%, 21%, and 27% moisture content. The actual
amounts of tobacco samples charged into the extraction vessels are
calculated based on moisture content to achieve the same amount (10
g) of oven-dried weight such that each sample subjected to the
extraction initially contains the same overall amount of tobacco.
Each sample is extracted and the resulting solid residues are
air-dried for at least 4 days to bring the moisture content of each
sample residue to relatively the same level.
[0072] For the fire-cured tobacco, increasing the moisture content
from 10% to 31% results in greater TSNA reduction (from 60% TSNA
reduction at 10% moisture content to 80% TSNA reduction at 31%
moisture content) and greater B[a]p reduction (from 45% B[a]p
reduction at 10% moisture content to 80% B[a]p reduction at 31%
moisture content).
[0073] For the water-extracted fire-cured tobacco, increasing the
moisture content from 10% to 27% similarly results in a greater
TSNA reduction (45% TSNA reduction at 10% moisture content to 80%
TSNA reduction at 27% moisture content) and a greater B[a]p
reduction (20% B[a]p reduction at 10% moisture content to 50% B[a]p
reduction at 27% moisture content).
[0074] Seemingly, introduction of moisture to the tobacco material
facilitates the removal of both B[a]p and TSNA. Although not
intended to be limiting of the invention, one explanation is that
the addition of water may open the internal structure of the
tobacco, leaving it more accessible for extraction. One other
explanation is that, because B[a]p is non-polar, the presence of
more water in the tobacco more effectively "pushes" the B[a]p out
of the tobacco. TSNA has both polar and non-polar features and
thus, this theory may explain the increase in both B[a].sub.p and
TSNA removal as the moisture level of the tobacco is increased.
Example 7
[0075] Various fire-cured and water-extracted fire cured tobacco
pulp samples are extracted using supercritical CO.sub.2 as
described in Example 3. Varying amounts of ethanol are added to act
as a modifier for the supercritical CO.sub.2 to evaluate the effect
of ethanol on the removal of B[a].sub.p and TSNA. Temperature and
pressure are also varied to evaluate the effect of these parameters
with the addition of ethanol to the extraction system. The pressure
is held at 10 or 20 MPa, the temperature is held at 40.degree. C.
or 60.degree. C., the flow rate is 10 mL/min CO.sub.2, and the run
time is 30 minutes. Varying amounts of ethanol are added to the
CO.sub.2 used to conduct extraction of the tobacco samples.
Specifically, the extraction media evaluated are: 100% CO.sub.2,
CO.sub.2 with 10% ethanol by weight, and CO.sub.2 with 30% ethanol
by volume. Extractions of both water-extracted and fire-cured
tobacco and fire-cured tobacco are conducted with each of these
extraction media. Extractions are conducted at temperatures of
40.degree. C. and 60.degree. C. and at pressures of 10 MPa and 20
MPa with each extraction medium. Each sample is extracted and the
resulting solid residues are evaluated to determine the reduction
in B [a]p and TSNA. For both the fire-cured tobacco and the
water-extracted fire-cured tobacco, adding ethanol results in a
greater reduction in both B[a]p and TSNA under all temperature and
pressure conditions evaluated.
[0076] For example, at 60.degree. C. and 10 MPa, extraction of
water-extracted fire-cured tobacco with CO.sub.2 alone results in a
20% reduction in B[a]p and a 32% reduction in TSNA, whereas
extraction with 30% ethanol in CO.sub.2 results in a 71% reduction
in B[a]p and a 79% reduction in TSNA. Under the same conditions,
extraction of fire-cured tobacco with CO.sub.2 alone results in a
37% reduction in B[a]p and a 46% reduction in TSNA, whereas
extraction with 30% ethanol in CO.sub.2 results in an 80% reduction
in B[a]p and a 75% reduction in TSNA.
[0077] The highest level of B[a]p reduction (74%) in
water-extracted fire-cured tobacco in this example is achieved with
an extraction medium of 30% ethanol in CO.sub.2 at a temperature of
60.degree. C. and a pressure of 20 MPa. The highest level of TSNA
reduction (79%) in water-extracted fire-cured tobacco in this
example is achieved with an extraction medium of 30% ethanol in
CO.sub.2 at a temperature of 60.degree. C. and a pressure of either
10 or 20 MPa.
[0078] The highest level of B[a]p reduction (80%) in fire-cured
tobacco in this example is achieved with an extraction medium of
30% ethanol in CO.sub.2 at a temperature of 60.degree. C. and a
pressure of 10 MPa. The highest level of TSNA reduction (75%) in
fire-cured tobacco in this example is achieved with an extraction
medium of 30% ethanol in CO.sub.2 at a temperature of 60.degree. C.
and a pressure of 10 MPa.
[0079] Generally, adding ethanol up to about 30% by volume to
CO.sub.2 for use as the extraction medium increases the removal of
both B[a]P and TSNA. Varying the temperature of such extractions
from 40.degree. C. to 60.degree. C. has little effect, although in
certain cases, it can result in slightly enhanced B[a]P and TSNA
removal. Similarly, increasing the pressure of such extractions
from 10 MPa to 20 MPa has little effect, although in certain cases,
it can result in slightly enhanced B[a]P and TSNA removal.
[0080] Many modifications and other embodiments of the invention
will come to mind to one skilled in the art to which this invention
pertains having the benefit of the teachings presented in the
foregoing description. Therefore, it is to be understood that the
invention is not to be limited to the specific embodiments
disclosed and that modifications and other embodiments are intended
to be included within the scope of the appended claims. Although
specific terms are employed herein, they are used in a generic and
descriptive sense only and not for purposes of limitation.
* * * * *
References